<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    .text{
        position: relative;
        width: 100%;
        height: 50px;
        line-height: 50px;
        text-align: center
    }
</style>
<body onload="startTime()">
<p class="text" onclick="f()">开始</p>
<p class="text"></p>
<script src="static/JS.js"></script>
</body>
</html>